Messages in this thread Patch in this message | | | Subject | Possible memory leak in request_firmware() | From | Catalin Marinas <> | Date | Tue, 07 Jul 2009 16:17:00 +0100 |
| |
Hi,
I get a couple kmemleak reports like below which I think happen on the failure path (-ENOENT) of a request_firmware() call:
unreferenced object 0xc355fdb0 (size 256): comm "NetworkManager", pid 2606, jiffies 4294902882 backtrace: [<c01e0c3a>] create_object+0xfa/0x250 [<c01e1e7d>] kmemleak_alloc+0x5d/0x70 [<c01dac1b>] kmem_cache_alloc+0x14b/0x190 [<c03a0c4c>] _request_firmware+0x11c/0x530 [<c03a1102>] request_firmware+0x12/0x20 [<f95f6591>] iwl_mac_start+0xa1/0x850 [iwlagn] [<f8fb08c1>] ieee80211_open+0x2e1/0x860 [mac80211] [<c048459a>] dev_open+0xba/0x100 [<c0483ab9>] dev_change_flags+0x139/0x1d0 [<c048d392>] do_setlink+0x282/0x410 [<c048ea81>] rtnl_setlink+0xf1/0x130 [<c048e285>] rtnetlink_rcv_msg+0x165/0x200 [<c049fac6>] netlink_rcv_skb+0x76/0xa0 [<c048e10e>] rtnetlink_rcv+0x1e/0x30 [<c049f7fb>] netlink_unicast+0x23b/0x250 [<c04a02db>] netlink_sendmsg+0x1db/0x2d0
The f_dev in _request_firmware() is allocated via the fw_setup_device() and fw_register_device() calls and its class set to firmware_class (the class release function is fw_dev_release).
Commit 6acf70f078ca replaced the kfree(dev) in fw_dev_release() with a put_device() call but my understanding is that the release function is called via put_device -> kobject_put -> kref_put -> koject_release etc. and it should call kfree since it's the last to see this device structure alive.
Because of that, the _request_firmware() function on its -ENOENT error path only calls device_unregister(f_dev) which would eventually call fw_dev_release() but there is no kfree (the subsequent put_device call would just make the kref negative).
The patch below may fix the problem but it's only later tonight that I can test it and confirm:
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index ddeb819..12e6e64 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -357,7 +357,7 @@ static void fw_dev_release(struct device *dev) kfree(fw_priv->pages); kfree(fw_priv->fw_id); kfree(fw_priv); - put_device(dev); + kfree(dev); module_put(THIS_MODULE); } @@ -407,14 +407,13 @@ static int fw_register_device(struct device **dev_p, const char *fw_name, retval = device_register(f_dev); if (retval) { dev_err(device, "%s: device_register failed\n", __func__); + kfree(fw_priv->fw_id); put_device(f_dev); - goto error_kfree_fw_id; + return retval; } *dev_p = f_dev; return 0; -error_kfree_fw_id: - kfree(fw_priv->fw_id); error_kfree: kfree(f_dev); kfree(fw_priv);
-- Catalin
| |